The present invention relates to the treatment of fabrics with conditioning agents (primarily perfume) during the home laundering operation. The invention herein utilizes friable microcapsules to carry the fabric conditioning agent to the fabrics being treated. Capsules containing the conditioning agent are made to attach themselves to fabrics in either the presoak bath or washing machine and are thereafter ruptured by manipulation of the fabrics to thereby release the conditioning agent.
The home laundering operation can provide an opportunity to treat fabrics being laundered with a variety of materials which impart some desirable benefit or quality to the fabrics during laundering. At each stage of the laundering operation (presoaking, washing, rinsing, drying) fabrics are, to varying degrees, found in contact with water which can provide the medium for delivery of fabric conditioning agents.
Delivery of fabric conditioning agents to fabrics during the laundering operation is not, however, accomplished without certain difficulties. Surfactants are generally employed during the presoaking and washing steps for the purpose of removing materials (soil) from the fabrics. Simultaneous deposition onto fabrics of fabric conditioning agents can, therefore, prove troublesome. While some of these problems can be overcome by conditioning fabrics in the automatic dryer (See, for example, Gaiser; U.S. Pat. No. 3,442,692; issued May 6, 1969), it is nevertheless exceptionally difficult to achieve efficient deposition in the dryer of those fabric conditioning agents such as perfume which are volatile and therefore susceptible to rapid evaporation in the dryer heat.
Attempts have been made to improve the efficiency of conditioning agent fabric deposition during the laundering process. For example, the copending U.S. patent application of Haug et al; Ser. No. 520,186; filed Nov. 1, 1974, involves the use of particulate sorbitan ester material as a fabric conditioning agent for use in home laundering. The copending U.S. patent application of Webb et al; Ser. No. 516,052; filed Oct. 18, 1974, involves the use of particulate starch material to deliver perfume to fabrics in the automatic dryer. In spite of these developments, there is a continuing need for methods and compositions which are suitable for efficiently and effectively delivering conditioning agents to fabrics during the home laundering operation.
Accordingly, it is an object of the present invention to provide granular presoaking/washing compositions which can deliver effective amounts of fabric conditioning agents to fabrics being laundered.
It is a further object of the present invention to provide an improved method for delivering fabric conditioning agents and especially volatile agents such as perfume to fabrics during the presoak or wash stage of the laundering process.
It has been surprisingly discovered that by utilizing particular types of conditioning agent-containing friable microcapsules in combination with certain types of capsule transfer agents, the above-enumerated objectives can be attained. Furthermore, methods and compositions can be realized which are unexpectedly superior to similar methods and compositions of the prior art. Athough treatment of fabrics with microcapsules is known (See, for example, Ida et al.; U.S. Pat. No. 3,870,542; issued Mar. 11, 1975; Bedenk et al.; U.S. patent application Ser. No. 586,448; filed June 12, 1975, and Pandell et al.; U.S. Pat. No. 3,632,296; issued Jan. 4, 1972), such prior art fabric treatment has generally required utilization of large numbers of microcapsules to provide effective capsule delivery. Furthermore, the prior art has not provided adequate methods or compositions suitable for microcapsule treatment of fabrics during the presoaking/washing stage of the home laundering operation.